The Case of the Quantum Brain

By George Johnson | March 7, 2013 12:09 pm

From A Shortcut Through Time by George Johnson. courtesy Alfred A. Knopf

There is another, rather mind-blowing explanation for how Oliver Sacks’s twins, in their contemplation of prime numbers, might perform billions of computations in their heads: their brains were quantum computers.

Consider, in a heroic suspension of disbelief, what that would mean. In an ordinary computer the elements that are manipulating the ones and zeroes of binary code are transistors or some kind of electronic switch. Tiny as they are — microscopic — each is still made of a huge number of atoms. They behave according to the crisp, hard-edged laws of classical mechanics.

Calculations in a quantum computer are performed instead by single atoms or single subatomic particles. A different, more fundamental kind of physics kicks in. All of the divisions required to test the primeness of a long number could be carried out simultaneously in quantum superposition (like Schrodinger’s Cats in various states of oneness and zeroness, dead and alive). The quantum counters — the qubits — are connected not with wires but through the phenomenon called quantum entanglement (Einstein’s “spooky action at a distance.”) And they are capable of factoring numbers (or so it has been demonstrated on paper) far faster than the most powerful digital machines. They can take a shortcut through time, which was the name of a book I wrote about the subject.

So, venturing further out on this limb (which is about to break any minute and plunge into the abyss below), let’s suppose that the twins weren’t calculating with their neurons, nature’s slow, squishy version of computer chips, but with the individual atoms from which the neurons are made.

Or, more specifically, with microtubules — units that make up the cytoskeleton of neurons and other cells. Stuart Hameroff at the University of Arizona has developed an elaborate theory in which electrons in this microscopic scaffolding can become entangled with electrons in the scaffolding of other neurons. The result would be a biological quantum computer. The theoretical physicist Roger Penrose, in three long books, lays out a forbiddingly complex argument in which quantum computation gives rise to human consciousness and the ability to commune with the mathematical purity of the Platonic realm. This is all part of a small school of thought that rejects the idea that the brain works by processing information — that what it does instead is noncomputational, as Sacks thought was true with the twins.

Hardly anyone else believes this. The reason we don’t see spooky superpositions out on the street is because the slightest jostling — one atom vibrating against another — will corrupt the quantum purity and cause the calculation to collapse. That is why the experimental quantum computers developed in physics labs operate only at temperatures near absolute zero.

And anyway — why would the twins be able to tap this deep well and perform great mathematical feats closed off to the rest of us?

There is a whole shelf of books on the notion that the brain is doing something beyond computation. The philosopher Colin McGinn gives a taste of this thinking in a review of Ray Kurzweil’s new book, How to Create a Mind, in the current New York Review of Books. I’ll be writing more about these things, on and off over the next year, but for now let’s consider a far likelier explanation for Sacks’s extraordinary report.

The twins were widely known for happily remembering and reciting long numbers. Maybe, unbeknown to Sacks, someone taught them a few six-digit primes. Or, as Pepijn van Erp suggests, it is not so unlikely that the brothers, in their numerical jousting, might have stumbled across a few primes by chance. When Sacks gave them a 10-digit prime they were simply marveling at its length not its nature, and then they matched it with some equally long number of their own.

Sacks never directly says — though he strongly implies it — that he checked the number in his book. And doubts have been raised (in a letter to The Journal of Autism and Developmental Disorders) about whether such a book even existed then. As the twins kept topping each other with longer and longer numbers there was, as Sacks writes, no way to check. And he didn’t save the information or consult someone with access to a computer that could have run a test. He had already convinced himself that his subjects had to be generating primes. So he moved on to the next neurological oddity that caught his attention.

Just last month (this was also in the NYRB) Sacks reflected on the fallibility of memory. He was describing a conversation he had with his older brother after the publication of Uncle Tungsten. In the memoir Sacks described a frightening experience from his childhood — when a German fire bomb landed in the back yard of the family home in London. But as he learned from his brother, they both had been away at boarding school when that happened. He had learned about the incident in a letter from his father. “A very vivid, dramatic letter,” his brother told him. “You were enthralled by it.”

Sacks was dumbfounded. “Although I now know, intellectually, that this memory was ‘false,’ it still seems to me as real, as intensely my own, as before.”

This is a prelude to a wonderful essay about cryptomnesia, embracing stories about Coleridge, Helen Keller, Ronald Reagan, George Harrison, Sigmund Freud, and the maverick ideas of neuroscientist Gerald Edelman (another NYRB regular). Sacks is a writer with a beautiful mind. He closes with his thoughts on memories not as recordings but as creations and re-creations — rough, malleable versions of the past.

“We, as human beings, are landed with memory systems that have fallibilities, frailties, and imperfections — but also great flexibility and creativity,” Sacks writes. What we believe and honestly report as fact can turn out to be artful embellishment. Stories too good to check.

Related posts:

Oliver Sacks and the Amazing Twins
The Mystical Mathematics of Rock and Roll
Idiot Savants and Prime Numbers

  • Buddy199

    This is similar to the theory that honey bees might using some form of quantum computing:

  • wbonesteel

    So, is Sacks’ memory of an event he didn’t experience possibly a verbal reinforcement of the quantum ‘transference’ of memory from one individual to another? Verbal description as a ‘cue’ or a ‘port’ for the quantum information to move from one brain (interface) to another? Also, a possible quantum ‘resonance’ contained in the memory. Intensity of emotion as a ‘reinforcement?
    Yeah, that’s a little out there, but it is an interesting thought experiment.

  • Richard Dickson

    The quantum brain argument could be explained by a treatise I collaborated on with my son, Robert Dickson, and is available via www. It’s entitled, “Toward a New Theory of Everything: Subatomic Wormholes, Space-Time, Quantum Entanglement, and the Nature of Gravity”. Basically, we develop the theory that space-time at its core quantum foam level is composed of Planck unit diameter wriggling wormholes, which appear and disappear within the quantum foam (based on Prof. Wheeler’s idea–circa 1955). Through these wriggling wormholes of space-time quantum particles travel, explaining the Feynmann diagrams and explaining near instantaneous quantum effects. Our wormhole theory of space-time also satisfactorily explains gravity as an effect, not a universal force; hence, one reason physicists have yet to discover the elusive gravity wave carrier particle, or graviton. We believe our new theory will eventually lead to completion of the Unified Field Theory, the “holy grail” of theoretical physics.The first application of our new theory could well be development of high-speed quantum macroscopic communications systems, which would lead to long-range space communications systems and possibly enabling us to contact other tech civilizations in the universe.

  • Brian J Flanagan

    So, I politely point out the flagrant errors in the article, provide relevant documentation and … You delete my comment?

    So much for the pursuit of truth, I guess. My respect for your publication has plummeted, quite possibly beyond retrieval.

    • byGeorgeJohnson

      Your comment wasn’t deleted, if you mean the one directly below.

      • Brian J Flanagan

        So it is … now.

        Are you the author of ‘Strange Beauty’? I thoroughly enjoyed it — unsparing, yet sympathetic.

        • byGeorgeJohnson

          Thank you so much. Indeed I am.

  • byGeorgeJohnson

    Well, of course. But the quantum mechanical aspects don’t affect the computation. They are in either of one state, 1 or 0.

    • Brian J Flanagan

      Yes, but that is another issue.

      I detect a whiff of formalism. The brain is not a digital computer and no such device has a hope in hell of instantiating consciousness. Why so?

      Let’s revisit Leibniz’s notion of the mill:

      “If we imagine a machine so constructed as to produce thought, sensation, perception, we may conceive it magnified — to such an extent that one might enter it like a mill. This being supposed, we should find in it on inspection only pieces which impel each other, but nothing which can explain a perception. It is in the simple substance, therefore, — not in the compound, or in the machinery, — that we must look for that phenomenon […]”

      Similarly, we cannot “produce thought, sensation, perception” in strings of 1’s and 0’s. We may mimic behavior, but that is not the same thing.

      I share your concerns about the complications in the Penrose- Hameroff approach, but Penrose was essentially correct when he called out the emperor’s new mind.

      Quantum theory provides us a path to the “simple substance.” In the case of color vision, a simple appeal to a mind/body identity theory, such as we find in Feigl, e.g., (and Pauli, of all people), we might well ask whether the visual field is a photon field. Can we put flesh on the bones of this conjecture?

      Helmholtz observed long ago that “similar light produces, under like conditions, a like sensation of color.” Spectral color is, of course,
      one of the “secondary qualities” of Locke, which he thought had only a mental existence. Why, then, discuss color in a physics journal? Is color not simply the wavelength of light? Well, no, contrary to what “everyone knows,” it is not.

      Feynman wrote that color “has always appealed to physicists and
      mathematicians,” and indeed it would be difficult to imagine a topic with a more illustrious history, populated as it is by Galileo, Newton, Young, Helmholtz, Hamilton, Riemann, Mach, Grassmann, Maxwell, Schrödinger, Weyl, Einstein et al. A handful of these authors tell us quite explicitly that color behaves like a vector. A wavelength, being a simple magnitude, is a scalar.

      Moreover, color is not properly incorporated into the body of our science, as traditionally formulated. When he wasn’t dabbling in quantum theory, Schrödinger wrote a handful of papers about color. Here he tells us like it is:

      “If you ask a physicist what is his idea of yellow light, he will tell you that it is transversal electromagnetic waves of wavelength in the
      neighborhood of 590 millimicrons. If you ask him: But where does yellow come in? he will say: In my picture not at all, but these kinds of vibrations, when they hit the retina of a healthy eye, give the person whose eye it is the sensation of yellow.”

      Now that we have found sure footing, we can both broaden and
      tighten the observation from Helmholtz with a little help from Heisenberg, and say that the same state vector [psi], acted upon by the same operators, produces the same spectrum of secondary qualities.

      Notice that thus far we have only recapitulated myriad familiar facts from everyday observation. Thus, we get up in the morning and
      things look, sound, taste and feel the way they always do—and where there are differences, we find physical causes for those differences. From a physical standpoint, it is naturally immaterial whether the relevant operator fields are located inside or outside the brain, thus obviating the putative “subjective” character of secondary sense-data.

      What has been gained? Perhaps a great deal, for as the
      mathematician Steen reminds us, early on in the history of quantum theory, the “mathematical machinery of quantum mechanics became that of spectral analysis.”

      A slightly subtler but fundamentally significant consideration attends those operators which leave color etc. invariant or
      symmetric, for here the subject opens out again into gauge theory, as well as both Lagrangian and Hamiltonian formulations of the equations of motion—and so all of physics and much of mathematics.

  • Edmond Xtime


    Do you define – MIND -?

    Everyone seems to be keenly emphatic about the subject of Time, and Mind.

    What is the simplest, and most concise definitions of either?

    And one more challenge; what I.S…? Thought.
    How does Change gets initiated?? What is the dynamo driving Change??,

  • slartibartfastibast

    Hartmut Neven has similar ideas:

    “Google Tech Talks – Quantum Computing Day 3: Does an Explanation of Higher Brain Function Require References to Quantum Mechanics?”

    As do I:


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Fire in the Mind

Whether a subtle new pattern shows up in an experiment on the Higgs boson, an epidemiological report about a suspected cancer cluster, or a double-blind trial purporting to demonstrate ESP, it can be maddeningly difficult to distinguish between what we see and what we think we see. "Fire in the Mind" takes a look at the big questions behind today’s science news.

About George Johnson

George Johnson writes about science for the New York Times, National Geographic Magazine, Slate, and other publications. His nine books include The Cancer Chronicles: Unlocking Medicine's Deepest Mystery (August 2013), The Ten Most Beautiful Experiments, A Shortcut Through Time, and Fire in the Mind. He is a winner of the AAAS Science Journalism Award and has twice been a finalist for the Royal Society science book prize. Co-founder and director of the Santa Fe Science Writing Workshop, he can be found on the Web at Twitter @byGeorgeJohnson.


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